• Energy Research
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• 2018 close
• 2021 close

Soil is a fundamental resource yet every year some 10 million ha of cropland are lost to soil erosion, mostly due to unsustainable agricultural and forestry practices. Erosion impacts overall sustainability in two ways: (a) reduction in farmland for food production, and (b) discharge of sediments and associated contaminants into water courses polluting water supply, fisheries and aquaculture, and reducing hydropower capacity due to reservoir siltation. Soil erosion and its environmental impacts sit centrally within the Energy-Food-Water-Environment Nexus. New approaches to land management change are required to reduce socio-economic impacts of soil erosion but in spite of its significance, soil erosion is insufficiently understood in its social dimensions, and is almost non-governed in Latin American DAC countries. Two factors may explain this: (a) erosion is often slow and "invisible", or accepted as the norm, and (b) erosion is highly complex, emerging from interaction of socio-economic and natural processes, with interconnected feedbacks between external and internal drivers. Working in collaboration with researchers from Argentina, Brazil, and Mexico, the Chile-UK partnership aims to develop a new integrated approach for understanding and governing soil erosion at the river basin scale. Our multidisciplinary team combines innovative scientific measuring methods and advanced Latin American approaches for socio-cultural intervention to provide a new framework within which soil erosion challenges in Latin America can be addressed.

There is much interest worldwide in energy storage, which is still currently dominated by pumped hydro. The new systems based on thermal storage (as opposed to chemical batteries and the like) that will be considered in this project show particular promise due to their relatively high energy density and the low cost of materials. This project will contribute to the body of work in this area that has been undertaken at CUED for several years and received excellent recognition, both nationally and internationally. It will link in to the EPSRC-funded Generation-Integrated Energy storage work. The project aims to explore the range of working fluids and cycle configurations (especially transcritical cycles) for thermo-mechanical energy storage technologies and develop design rules based based on concepts such as power density and energy density. In the current literature, few working fluids have been compared in terms of their performance, and transcritical cycles have been relatively sparsely studied. This will be mainly computer-based, with cycle analysis methods coded in Matlab or Python. Furthermore, the project will include developing accurate cost models for the aforementioned cycle configurations. This will enable cost-efficiency optimisation thereof.

On our planet, solar energy is an abundant renewable resource. The conversion of solar into thermal energy is currently the most efficient way to use this resource. Concentrated Solar Power plants, which use mirrors to focus the solar energy to generate high temperatures, are however costly, and require large installations. Flat plate collectors, which today have efficiencies of 50% at a temperature of 120C, are potentially a cost effective solution. The problem here lies in the conversion of this low-grade heat into usable energy. At Southampton University, we recently developed the condensing engine (CE) - a heat engine which employs water as working fluid with an operating temperature of 100C. The engine uses the condensation of steam and the arising vacuum as driving force, rather than the pressure of steam. It operates at atmospheric pressure, so that safety issues are minimal. The use of steam expansion gives an efficiency of 10% or more. In combination with flat plate collectors, the CE has the potential for the development of a simple, cost-effective, modular solar thermal system, which produces electricity as well as fresh water from the condensation process. In this project, we will develop a theoretical framework for a solar thermal system for electricity production and desalination with the aim to assess its overall productivity. For the key component, the condensing engine, a theoretical model will be developed.as basis for its optimisation. Based on the results, an experimental 100 Watt engine will be built and tested. Recent theoretical work suggests that through heat recovery from the condensation process, the power output can be increased by 30-35%, and the water production by 70 to 80%. This would lead to a novel, 2-stage energy conversion cycle and would improve the cost-effectiveness of the system substantially. The heat-recovery condensation process will be developed, modelled, and tested in the laboratory. The project will result in an optimised solar thermal energy and desalination system with novel, efficient and cost-effective components. The project runs in cooperation with Synext Ltd., Delft/Netherlands. The simplicity of the system, and its modular character mean that it would also be well suited for deployment in developing countries where there is an urgent need for both energy and clean water. This aspect will also be explored in cooperation with synext Ltd.

There is much interest worldwide in energy storage, which is still currently dominated by pumped hydro. The new systems based on thermal storage (as opposed to chemical batteries and the like) that will be considered in this project show particular promise due to their relatively high energy density and the low cost of materials. This project will contribute to the body of work in this area that has been undertaken at CUED for several years and received excellent recognition, both nationally and internationally. It will link in to the EPSRC-funded Generation-Integrated Energy storage work. The project aims to explore the range of working fluids and cycle configurations (especially transcritical cycles) for thermo-mechanical energy storage technologies and develop design rules based based on concepts such as power density and energy density. In the current literature, few working fluids have been compared in terms of their performance, and transcritical cycles have been relatively sparsely studied. This will be mainly computer-based, with cycle analysis methods coded in Matlab or Python. Furthermore, the project will include developing accurate cost models for the aforementioned cycle configurations. This will enable cost-efficiency optimisation thereof.

Awaiting Public Project Summary

The Erigeneia project targets to enable the high penetration of PV technology and to utilize its potential value in the energy system by developing a local and central energy management system (EMS) that will combine photovoltaics (PV) with battery energy storage systems (BESS). The project will match the technical requirements imposed by the distribution system operators (DSO) with the upcoming new market regulations, capitalizing on the positive effects of PV and BESS combination. In addition, a tool for intra-hour energy forecasting will be developed and integrated into the EMS to provide a more accurate and reliable operation plan for the DSO. The proposed work is expected to have significant impact on the further penetration of PV given that the existing grid infrastructure will be utilized in a more efficient way, by increasing the hosting capacity hence deferring grid reinforcement. By promoting grid-friendly self-consumption of PV generation, grid congestion issues will be avoided. Since the EMS will increase the power usage predictability, the current expensive power reserves will be replaced by the local EMS control strategies of the combined PV and BESS EMS. Furthermore, the users will take advantage of the provided flexibility in order to lower their cost of electricity, by gaining from the new upcoming policies of Time of Use (ToU) and dynamic tariffs. Finally, a versatile algorithm capable of estimating the optimum size of BESS and PV to meet all the needs of prosumers will also be developed. Field trials will take place in Cyprus (domestic EMS) and Turkey (community EMS) and novel or more effective ancillary services will be provided to the network operators (e.g. power smoothing, voltage regulation). Finally, the economic impact of the proposed solutions will be quantified. The proposal is fully in line with the SET plan and Solar Energy Industrial Initiative objectives for effective integration of solar energy technologies in the energy system.

The growing need for energy by our society and the depletion of conventional energy sources demands the development and improvement of safe, renewable and low-cost clean energy technologies. Photovoltaic (PV) technology which makes use of the super-abundant and freely available Sun's energy to generate electricity has obvious economic, environmental and societal benefits. However, in order for PV technology to provide a significant fraction of the world's energy demands, devices must be composed of cheap and earth-abundant materials. Science and engineering are in a unique position to address the challenge to discover, design and develop inexpensive, non-toxic, and earth-abundant new materials that exhibit the ideal electronic properties for PV applications. This proposal outlines the strategy for the rational design of zinc phosphide (Zn3P2) heterojunctions for the efficient conversion of solar energy into electricity. Zinc phosphide is ideally positioned as a next-generation PV material due to its direct band gap of 1.50 eV, which allows it to absorb a high percentage of the solar spectrum. Zn3P2 also has a high visible-light absorption coefficient, long minority-carrier diffusion length, a large range of potential doping concentrations, and both of its constituent elements are non-toxic, cheap and abundant, which makes Zn3P2 a promising material for cost-effective and scalable thin-film photovoltaic applications. Despite its germane electronic properties, to date, a Zn3P2 device of sufficient efficiency for commercial applications has not been demonstrated. The highest solar energy-conversion efficiencies of 6.0% for multi-crystalline and 4.3% for thin-film cells have been reported. The low efficiencies of the thin film and heterojunction-based Zn3P2 devices have been attributed to poor understanding of the interfaces and band-alignment between the emitter and the absorber layers, to high concentrations of interface trap states (Fermi-level pinning), and/or to inadequate interface passivation. Given their 2-dimensional nature and their typical location buried within bulk materials, interfaces are difficult to resolve or access by purely experimental means. The goal of this cross-disciplinary project is, therefore, to develop and employ a combination of cutting-edge computational techniques and experiment to design and identify the key interfacial and electronic properties needed for the practical performance of zinc phosphide photovoltaics to achieve improved solar energy-conversion efficiencies. The use of a synergistic computational-experimental approach will help address key questions about the nature of atomic ordering (chemical and structural) and the electronic properties of the surface and interface of epitaxial Zn3P2 films grown on II-VI and III-V substrates, which will unlock a promising pathway towards the development and commercialization of low-cost, high-efficiency and earth-abundant Zn3P2 photovoltaic devices. The innovation of the proposed project is based on the engineering and transformation of earth-abundant and non-toxic Zn3P2 into a cost-effective, highly efficient and scalable thin-film PV material that provides additional environmental, health and economic benefits to the UK and globally. The main deliverables and benefits of the proposed project include, but are not limited to (i) atomic-level understanding of the surface and interface properties of a Zn3P2 epilayer, which has important implications on device fabrication and performance; and (ii) the growth of high-quality epitaxial Zn3P2 films on II-VI and III-V substrates as proto-types for industrial-scale PV applications.